Double throw safety for transfer apparatus for of die casting machines



'. H. MORIN 2,542,556

ETY FOR TRANSFER APPARATUS oF Dn: CASTING MACHINES Filed July 3 1947 Feb. 20, 1951 DOUBLE THROW s Patented Feb.A 20, 1951 UNITED STATES PATENT OFFICE DOUBLE THROW SAFETY FOR TRANSFER APPARATUS OF DIE CASTING MACHINES Louis H. Morin, Bronx, N. Y.

Application July 3, 1947, Serial N o. 758,867

3 Claims. 1

This invention relates to die casting machines of the type and kind wherein acasting is formed on a transfer pin or member used for stripping the casting from the dies and to move the casting to trimming and stripper stations. More particularly, the invention deals with apparatus of the character described, wherein safety means is provided in the drive or feed of the transfer mechanism whereby, in the event of this mechanism or the pin there-of striking an obstruction or any means blocking its normal path of travel, the drive will yield to compensate for this blockage or stoppage without effecting injury to the machine or the respective parts thereof. Still more particularly, the apparatus includes means for pneumatically actuating a stripper when the transfer pin is positioned at the stripper station.

The novel features of the invention will be best understood from the following description, when taken together with the accompanying drawing, in which certain embodiments of the invention are discosed and, in which the separate parts are designated by suitable reference characters in each of the views and, vin which:

Fig. l is a partial front and sectional view of the double throw safety mechanism for transfer apparatus of a die casting machine.

Fig. 2 is a sectional View substantially on the line 2 2 of Fig. l; and

Fig. 3 is a view partially similar to Fig. 2 and showing only a part of the construction and showing the face View of one die part and indicating the operation in one blocking of the transfer mechanism.

My present invention deals with die casting machines of the type kand kind more fully disclosed in a companion application, entitled Hydraulic Die Casting Machine, Serial No. 753,190, filed June 7, 1947. In the present drawing, I have shown only such parts of the machine as relate primarily to my improved double throw safety stop for the transfer apparatus or mechanism of the machine.

In Fig. 1 of the drawing, I have shown at- III, Iii a pair of dies, on abutting surfaces of which are formed an impression Il, vto form a suitable die casting, as at I2. The dies are mounted on suitable supports i3, I3 actuated in any desired manner in movement of the dies toward and from each other. Adjacent surfaces of the dies are fashioned to form a recess for a transfer pin or nger I4 which extends into the cavity Il so that the casting I2 is formed on the pin.

Considering Figs. 2 and 3 of the drawing, it will appear that suitable guides. as at I5, I5',

are provided for the dies and their supports I3, I3 and in Fig. 2 I have indicated, at IG, the discharge nozzle, through which casting material may be injected into the die cavity II through a conventional gate, as at Il. At I8 I have shown part of the frame of the machine having spaced bearings I9 and 20, in which are rotatably mounted two shafts 2I, 22. Secured to the shaft 22` is a substantialy T-shaped housing 23 having, centrally of the lower portion, an air cylinder 24, into which air under pressure is admitted through a pipe 25, which extends through the shaft 2i. In the cylinder 24 is arranged a piston or plunger 26 held in a depressed position by a spring 2l engaging the head end 28 of a stripper rod 29. The rod 29 is slidably mounted in a bushing 30 adjustably clamped in the upper portion 3l of the housing 23. Clamped to one side of the bushing 30, as seen at 32, is the pin or finger I4. The end of the transfer pin I4 may be adjusted radially or vertically with respect to the faces of the dies I, I0 for various sizes and shapes of casting by adjusting the position of the bushing 30 in the housing 23 or by adjusting the position of the clamp 32 on the bushing 30. Secured to the upper end of the rod 29 is a fork-shaped stripper element 33. The head 28 is held in engagement with the piston 26 by the spring and, as air under pressure is timely admitted to the cylinder 24, the piston is moved upwardly thus moving the stripper element 33 longitudinally of the pin I4 to strip that part of the casting which is st'll remaining on the pin. This operation is performed at a stripper station, later described.

The shaft 22 projects beyond its bearing 20 and secured thereto is a gear segment 34 adjustably clamped on the shaft by screws 35 passed through the split portion 36, as seen in Fig. 2. The segment 34 also includes a flange portion 31 operating inea guide 38, which, in conjunction with the frame I8 or the bearing 2li, maintains the shaft 22 against longitudinal movement.

Arranged below the shaft 22 and suitably supported in the frame I8 is a stub shaft 39, on which is rotatably mounted a gear segment lili which meshes with the segment 34 and which is engaged by an operating lever 4| also mounted on the shaft 39. The gear segment 4G has an offset U-shaped portion, as at 42, note Fig. 1, in the aperture 43 of which is pivoted, as at 44, a rod 45. The lever 4I has an offset apertured arm 46, through which the rod 45 passes and seating on this arm is a spring 4l, the tension of which is adjusted by nuts 48 on theend of the rod H45.

The lever 4i has a forked end portion 49, in which is pivoted an arm end 5G of a O-frame 5I. The frame 5l has an aperture 52 through which the drive shaft 53 of the machine extends, the frame being guided in its movement with respect to the shaft 53 by a suitable bearing, as at 5d. The outer end of the frame supports a roller 55, which is movable over the surface 56 of a control cam 5'? keyed to and actuated by the shaft 53.V

Supported by a suitable bracket 58 on the frame i8 is another rod 59 having a forked end SG pivoted to the O-frame 5l, as at 6l. Adjust-` ably mounted on the end of the rod 59 are nuts 62 between which and the bracket 58 is arranged a spring 63. The spring 63 supports the frame 5l with the roller 55 thereof in constant engagement with the surface 55 of theY cam 5l and thus is of suiioient tension to operate the transfer mechanism in conjunction with the cam 5i, that is to say, to rotate the shafts 2 l 22 with the housing 23 thereon in swinging the pin i4 from its position between the dies, where it has received a casting, as at l2, first to a trimming station, which position is indicated by the dot dash line X (Fig. 2); then to a stripper station, indicated by the dot dash line X2, and then back to position between the dies.

In Fig. 3 of the drawing, I have shown the pin or finger i4 at the stripper station with the stripper element 33 extended to remove that part of the casting which remains on the pin, after the pin has moved to the stripper station from the trimming station. In this figure, I have also illustrated an operation of one of the safety mechanisms from the standpoint that it can be assumed that the housing 23 in some manner or other became blocked at the stripper station and the cam 5T had continued its operation to return the pin lli to position between the dies or the position shown in Fig. 2. Here the cam El, as well as the frame 5i and the lever 4|, has carried through its normal stroke motion, but no movement has been contributed to the finger lit thus maintaining the gear segments lili, 3eV in their meshed relationship. It will thus be seen that the rod 45 has been drawn through the apertured nger 46 causing the spring 4I to be compressed, thus permitting the positively driven parts of the mechanism to continue to move and compensating for this blocking movement. It will here be understood that this operation can take place anywhere between the trimming station and return of the finger lili to position-between the dies.

On the other hand, should the finger i4 or its associated parts, comprising the housing 23, be blocked, in its downward movement or movement from position between the dies to the trimming station, the spring 63 will operate as the safety medium. In other words, let us assume that any part of the transfer mechanism, in-

cluding the gear segments 34, lili, the lever lil, or

the frame 5I were blocked while in the position shown in Fig. 2, or at the moment that the depression surface 56' of the cam 5l reach theA roller 5E, the blocking of the parts in question would simply maintain the frame 5i in the position as shown in Fig. 2 and allow the cam 57i' to rotate freely without having controlled in any movement of the frame. This action can take place at any stage of operation of the transfer mechanism in the aforesaid movement from the die position to the trimming position.

Considering Fig. 2 of the drawing, it wiil appear that the apertured finger 4610i the lever 4l will strike the surfaces 64 of the yoke-shaped portion 42 of the gear segment in rotating said segment to move the transfer pin or finger I4 from the die position to the trimming station. In the reverse operation, the gear segment 40 is rotated by the lever 5B acting against the spring 41 which is sufficiently tensioned to actuate the transfer mechanism and, yet, to yield in the manner illustrated in Fig. 3, should any blocking or stoppage occur to said mechanism.

From the foregoing, it will appear that, what I term a double throw safety is provided for the transfer apparatus or mechanism of a casting machine of the kind under consideration, thus providing fool-proof operation of the machine, particularly insofar as the apparatus or mechanism in question is concerned.

It will be apparent that the transfer mechanism, of which the pin or core I4 forms a part, is actuated by the cam 57 and frame 5i through the lever 4I and the gear segments 34 and iii to move the same from the casting station to the trimming station, the stripper station and, then, back to the casting station. In the first of these movements, the lever positively actuates one of the gear segments, but the drive to the lever is yieldable, whereas in other or return movements, the drive of said gear segments by the lever is through the spring el. In other words, there are two throws to the transfer mechanism and, in both throws, a safety factor is provided.

I-Iaving fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A transfer mechanism for moving a casting formed between a pair of dies of a die casting machine to a stripping station spaced with respect to the dies, said mechanism comprising a pair of shafts mounted for rotation in spaced bearings, a housing joining adjacent ends of the shafts and rotatable therewith, a bushing adjustably supported in said housing, a plunger reciprocably mounted in said bushing and projecting therefrom, a transfer member on which a casting is adapted to be formed adjustably secured to said bushing with one end of said transfer member projecting to a position between said dies, means at one end of one of said shafts for actuating the shaft to swing the transfer member to and from its position between the dies and a stripping station, a stripper carried on said plunger adjacent said transfer member, and air operated means for moving said plunger and stripper longitudinally of said transfer member for stripping a casting from said transfer member when the latter is at the stripping station.

2. In a transfer mechanism for moving a casting from between a pair of movable dies in a die casting machine to stations spaced with respect to said dies for trimming and stripping operations at said stations, the combination which includes a pair of shafts mounted for rotation in spaced bearings, a housing joining the ends of said shafts and being rotatable therewith, an air cylinder located within the housing, an air actuated plunger located within the cylinder with one end of said plunger extending beyond the housing, a support secured to said housing, said support being adjustable in a plane paralleling the sides of the dies, a transfer pin carriedvby said support, said transfer pin having one end thereof projecting between opposing faces of the movable dies and being adjustable lengthwise in the lsupport and transversely of thefaces of the dies. and a stripper carried by the air actuated plunger adjacent the ltransfer pin, said plunger being rotatable in the housing for positioning the stripper carried thereon adjacent to the transfer pin and being movable lengthwise of the transfer pin upon admission of air under pressure to the air cylinder for moving the stripper to the end of the transfer pin.

3. In a transfer mechanism for moving a casting from between a pair of movable dies in a die casting machine to stations spaced with respect to said dies for trimming and stripping operations at said stations, the combination which includes a pair of shafts mounted for rotation in spaced bearings, a housing joining the ends of said shafts and being rotatable therewith, a support secured to said housing, said support being adjustable in a plane paralleling the sides of the dies, a transfer pin carried by said support, said transfer pin having one end thereof projecting between opposing faces of the movable dies and being adjustable lengthwise in the support and transversely of the faces ofthe dies, a cylinder located within the housing, a uid actuated plunger located within the cylinder with one end of said plunger extending beyond the housing adjacent said transfer pin, a stripper carried by said plunger, said plunger being rotatable in the housing for positioning the stripper carried thereon alongside of the transfer pin and being movable lengthwise of the transfer pin upon admission of air under pressure to the air cylinder for moving the stripper to the end of the transfer pin, a drive shaft and connections between said drive shaft and the end of one of the shafts supporting the housing fer rocking said shafts and the housing and moving the transfer pin carried thereby from between the dies and then returning the same, said connections including a pair of springs normally maintaining the connections between the driving shaft and the first-mentioned shaft, said springs permitting the driving shaft to continue to rotate upon the transfer pin being held against movement in either direction.

LOUIS H. MORIN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,266,787 Morin f- Dec. 23, 1941 2,367,303 Morin Jan. 16, 1945 

